Character Types

The fundamental character types are AnsiChar and WideChar. AnsiChar values are byte-sized (8-bit) characters ordered according to the locale character set which is possibly multibyte. AnsiChar was originally modeled after the ANSI character set (thus its name) but has now been broadened to refer to the current locale character set.

WideChar characters use more than one byte to represent every character. In the current implementations, WideChar is word-sized (16-bit) characters ordered according to the Unicode character set (note that it could be longer in future implementations). The first 256 Unicode characters correspond to the ANSI characters.

The generic character type is Char, which is equivalent to AnsiChar on Win32, and to Char on the .NET platform. Because the implementation of Char is subject to change, it's a good idea to use the standard function sizeOf rather than a hard-coded constant when writing programs that may need to handle characters of different sizes.

Note: The WideChar type also maps to Char on the .NET platform. A string constant of length 1, such as 'A', can denote a character value. The predefined function Chr returns the character value for any integer in the range of AnsiChar or WideChar; for example, Chr (65) returns the letter A.

Character values, like integers, wrap around when decremented or incremented past the beginning or end of their range (unless range-checking is enabled). For example, after execution of the code var

Letter: Char; I: Integer; begin

Letter := High(Letter); for I := 1 to 66 do Inc(Letter);

end;

Letter has the value A (ASCII 65).

Project Management Made Easy

Project Management Made Easy

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